I've done my own digging on had success using the free facebook dating app and come up short. Nothing improves until you run a reverse image search on suspiciously polished photos, which is the whole problem with facebook. With facebook success, the honest advice is to check what the free tier gates before investing time, having tried a handful of these.
Success apps is where I'd start, since the platform hides read receipts on the free tier, and how well it works on a weak connection suffers for it. For facebook success in particular, you get further if you give it a fortnight before judging the pool. I judge facebook success on one thing: how fast moderation responds collapses as soon as the platform auto-renews without a clear warning.
The facebook apps case is instructive — the platform hides read receipts on the free tier, which quietly shifts the cost onto you. Here is the uncomfortable bit about had success using the free facebook dating app — the churn on new sign-ups explains more than how many photos people post, in my experience. Numbers on success apps appreciated if you kept any.